Motion Path Question

I am looking to reverse a motion path when an answer is answered incorrectly.  For example, the object is a set of stairs and if the correct answer is "Yes", the motion path advances up one step, however, if they answer the incorrect answer "No", the motion path advances down a step and can only advance up a step again if the next question is answered correctly.

1.  How do I only allow the subject to choose one answer or the other and not choose both answers?  (I am using the checkbox controls for the answers)


1 Reply